Protective leakage shield for liquid to air heat exchanger

ABSTRACT

A leakage shield for an air to liquid heat exchanger includes a drain pan, a liquid header panel, and a closure bar. The drain pan has a first side and a second side opposite the first side. The liquid header panel has a lower end attached to the first side of the drain pan, and extends vertically upwards from the first side of the drain pan. The closure bar panel has a lower end attached to the second side of the drain pan, and extends vertically upwards from the second side of the drain pan.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This divisional application claims priority from application Ser. No.13/236,979, filed Sep. 20, 2011, entitled PROTECTIVE LEAKAGE SHIELD FORLIQUID TO AIR HEAT EXCHANGER, which is hereby incorporated by reference.

BACKGROUND

The present disclosure relates generally to heat exchangers and morespecifically, to leakage shields for liquid to air heat exchangers.

Airplane cabins require a constant flow of conditioned air. It is commonto equip an airplane with an environmental control system for providingconditioned air to the cabin and other pressurized regions. Knownenvironmental control systems can be further subdivided into an aircycle system responsible for obtaining fresh exterior air and an airrecirculation system responsible for obtaining used cabin air. The aircycle system and air recirculation system commonly overlap at an airmixer where a portion of fresh exterior air is mixed with a portion ofused cabin air to produce a mixed airstream for distribution to thecabin.

Environmental control systems usually include heat exchangers forcooling air prior to entry into the cabin. Both air-to-air heatexchangers and liquid-to-air heat exchangers are frequently operated inenvironmental control systems. Most commonly, heat exchangers are placedwithin an air conditioning pack of the air cycle system for coolingfresh exterior air prior to mixing with recirculation air andintroduction into the cabin.

SUMMARY

A heat exchanger includes an air inlet, an air outlet, a liquid inlet, aliquid outlet, a drain pan, a liquid header panel, and a closure barpanel. The air inlet is located on a first side and the air outlet islocated on a second side opposite the first side. The liquid inlet andthe liquid outlet are located on a third side, where the third sideextends between the first side and the second side. The drain pan coversa bottom, the liquid header panel covers the third side, and the closurebar panel covers a forth side opposite the third side, where the fourthside extends between the first side and the second side. The drain pan,liquid header panel, and closure bar panel form a shield preventingliquid leakage from the heat exchanger.

A leakage shield for an air to liquid heat exchanger includes a drainpan, a liquid header panel, and a closure bar. The drain pan has a firstside and a second side opposite the first side. The liquid header panelhas an upper end attached to a first mounting bracket, a lower endattached to the first side of the drain pan, and a central portionextending vertically upwards from the first side of the drain pan. Theclosure bar panel has an upper end attached to a second mountingbracket, a lower end attached to the second side of the drain pan, and acentral portion extending vertically upwards from the second side of thedrain pan.

A method of installing a leakage shield on a liquid to air heatexchanger includes covering a bottom of the heat exchanger with a drainpan. The method further includes covering a first side of the heatexchanger with a liquid header panel and covering a second side of theheat exchanger with a closure bar panel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cut-away view of an airplane having a heat exchanger inaccordance with the present disclosure.

FIG. 2 is a schematic representation of fluid flow to and from the heatexchanger of FIG. 1.

FIG. 3 is a side view of the heat exchanger of FIGS. 1 and 2.

FIG. 4 is a front perspective view of the heat exchanger of FIG. 3 witha leakage shield exploded therefrom.

FIG. 5 is a bottom perspective view of the heat exchanger and explodedleakage shield of FIG. 4.

FIG. 6 is a top perspective view of the heat exchanger and explodedleakage shield of FIGS. 4 and 5.

FIG. 7 is a front perspective view of the heat exchanger with leakageshield assembled of FIGS. 4-6.

DETAILED DESCRIPTION

As used herein, the term “airplane” includes any type of aircraft havinga cabin and recirculation system. FIG. 1 is a cut-away view of airplane10 having heat exchanger 12 in accordance with the present disclosure.Airplane 10 includes passenger cabin 14 having floor 16 and ceiling 18.Located below floor 16 is lower ducting 20, and located above ceiling 18is upper ducting 22, which is attached to heat exchanger 12. Air fromcabin 14 is drawn into upper ducting 22 above ceiling 18 for cooling byheat exchanger 12 before being returned to cabin 14.

As shown in FIG. 1, airplane 10 is a commercial jetliner having cabin 14for transporting passengers. Cabin 14 is defined at a bottom by floor 16and at a top by ceiling 18. Heat exchanger 12 is attached to upperducting 22 and is located in the area above ceiling 18, otherwise knownas the “crown” of airplane 10. A first portion of used cabin air isdrawn from a bottom of cabin 14 through floor 16 and into lower ducting20. This first portion of used cabin air is ducted through lower ducting20 to an unpressurized region of airplane 10 for mixing with fresh,conditioned air in an air mixer. A second portion of used cabin air isdrawn from a top of cabin 14 through ceiling 18 and into upper ducting22. This second portion of used cabin air is sent through upper ducting22 and to heat exchanger 12 in the crown of the airplane, which is apressurized region of airplane 10 like cabin 14. Heat exchanger 12 coolsthis second portion of relatively warm, used cabin air such that itbecomes relatively cool, conditioned recirculation air. Thisrecirculation air is then ducted from heat exchanger 12 throughdistribution ducting and directly back into cabin 14 for re-use bypassengers.

FIG. 2 is a schematic representation of fluid flow to and from heatexchanger 12. Depicted in FIG. 2 are heat exchanger 12, cabin 14, warmair 24, cool air 26, cool liquid 28, warm liquid 30, air inlet 32, airoutlet 34, liquid inlet 36, liquid outlet 38, integrated cooling system(ICS) 40, fan 42, diverter valve 44, and liquid bypass 46. Cool liquid28 cools warm air 24 within heat exchanger 12 thereby producing cool air26 and warm liquid 30.

Heat exchanger 12 is a liquid to air heat exchanger located in thepressurized crown region of airplane 10 for locally cooling cabin air,such as the second portion of used cabin air discussed with reference toFIG. 1. Warm air 24 is ducted from cabin 14 to heat exchanger 12. Warmair 24 is cooled within heat exchanger 12 to become cool air 26. Coolair 26 is sent from heat exchanger 12 through distribution ducting andback to cabin 14 as a recirculation airstream. Cool liquid 28 is pipedfrom integrated cooling system (ICS) 40 to heat exchanger 12. In thedepicted embodiment, the liquid is propylene gylcol-water (PGW) that hasbeen chilled by a vapor cycle and used to cool the galley cooling unitsbefore being sent to heat exchanger 12 as cool liquid 28. Within heatexchanger 12, warm air 24 rejects heat into cool liquid 28, whichbecomes warm liquid 30. Warm liquid 30 exits heat exchanger 12 and ispiped back into ICS 40. In the embodiment depicted, warm liquid 30 issent from heat exchanger 12 to a condenser associated with the air cyclesystem in an unpressurized region of the airplane.

Warm air 24 enters heat exchanger 12 at air inlet 32, and cool air 26exits heat exchanger 12 at air outlet 34. Cool liquid 28 enters heatexchanger 12 at liquid inlet 36, and warm liquid 30 exits heat exchanger12 at liquid outlet 38. Fan 42 is located between cabin 14 and heatexchanger 12 to pull warm air 24 from cabin 14 into heat exchanger 12.Diverter valve 44 is located between ICS 40 and heat exchanger 12 todivert a portion of cool liquid 28 from ICS 40 around heat exchanger 12through liquid bypass 46. For example, when cooling demand for heatexchanger 12 is lower, an increased portion of cool liquid 28 is sentthrough liquid bypass 46 around heat exchanger 12. The specificarchitecture of heat exchanger 12 is discussed below with reference toFIG. 3.

FIG. 3 is a side view of heat exchanger 12 from FIGS. 1 and 2. Depictedin FIG. 3 are heat exchanger 12, air inlet 32, air outlet 34, liquidinlet 36, liquid outlet 38, top 48, bottom 50, first side 52, secondside 54, third side 56, 3-way mount 58, liquid drain 60, bosses 62, airinlet header 64, air outlet header 66, and condensation drain 68. Heatexchanger 12 is configured to reject heat from air to liquid, therebylocally cooling air for recirculation and reuse.

As described above with respect to FIG. 2, heat exchanger 12 includesair inlet 32, air outlet 34, liquid inlet 36, and liquid outlet 38. Heatexchanger 12 is defined by top 48, bottom 50, and four sides, three ofwhich are visible in FIG. 3: first side 52, second side 54, and thirdside 56. Top 48 includes 3-way mount 58 for securing heat exchanger 12into the crown of airplane 10. Bottom 50 is located opposite of top 52.Liquid drain 60 and bosses 62 extend vertically downwards from bottom50. Liquid drain 60 can be attached to tubing to direct excess liquidaway from heat exchanger 12 and bosses 62 are welded to an end sheet ofheat exchanger 12 to mount a drain pan (described below with referenceto FIGS. 4-7). First side 52 of heat exchanger 12 is attached to airinlet header 64 which defines air inlet 32 for receiving warm air 24from cabin 14. Second side 54 of heat exchanger 12 is located oppositefirst side 52. Second side 52 is attached to air outlet header 66 whichdefines air outlet 34 for directing cool air 26 from heat exchanger 12back to distribution ducting, and eventually cabin 14. Condensationdrain 68 extends vertically downwards from a bottom of air outlet header66 for directing condensed water away from the air stream. Like liquiddrain 60, condensation drain 68 can be attached to tubing that directsexcess water away from heat exchanger 12.

FIGS. 4-6 are perspective views of heat exchanger 12 from FIG. 3 withleakage shield 70 exploded therefrom. FIG. 7 is a perspective view ofheat exchanger 12 with heat shield 70 fully assembled. Depictedthroughout FIGS. 4-7 are the components of heat exchanger 12: liquidinlet 36, liquid outlet 38, top 48, bottom 50, first side 52, secondside 54, third side 56, 3-way mount 58, bosses 62, air inlet header 64,air outlet header 66, fourth side 72, and 1-way mount 74. Also shownthroughout FIGS. 4-7 are the components of leakage shield 70: drain pan76, liquid header panel 78, and closure bar panel 80. Drain pan 76includes lip 82, depression 84, drain hole 86, and bosses 88. Liquidheader panel 78 includes top 90, bottom 92, first side 94, second side96, inlet opening 98, and outlet opening 100. Closure bar panel 80includes top 102, bottom 104, first side 106, and second side 108. Drainpan 76, liquid header panel 78, and closure bar panel 80 are securedaround heat exchanger 12 to from leakage shield 70.

The structure of heat exchanger 12 is described above with reference toFIG. 3. The discussion of FIGS. 4-7 will focus on the structure ofleakage shield 70 and its attachment to heat exchanger 12. Leakageshield 70 includes drain pan 76 for covering bottom 50 of heat exchanger12, liquid header panel 78 for covering third side 56 of heat exchanger12, and closure bar panel 80 for covering fourth side 72 of heatexchanger 12. Leakage shield 70 can be formed from metal or plastic.When assembled as shown in FIG. 7, leakage shield 70 prevents liquidfrom escaping heat exchanger 12. When heat exchanger 12 is installed inaircraft 10, leakage shield 70 will protect the crown, as well as cabin14, from fluid leakage and any water condensation created on exteriorsurfaces of heat exchanger 12.

Drain pan 76 includes lip 82, depression 84, drain hole 86, and bosses88. Lip 82 extends upwardly from each of the four sides of drain pan 76to form an upstanding rectangle. Depression 84 is located centrallywithin a center of drain pan 76. Drain hole 86 is located centrallywithin depression 84 and can be attached to tubing for directing anyliquid collected within drain pan 76 away from heat exchanger 12. Bosses88 extend through a bottom surface of drain pan 76 are aligned withbosses 62 extending from bottom 50 of heat exchanger 12. Bolts can beinserted through bosses 88 of drain pan and into bosses 62 of heatexchanger 12 to secure drain pan 76 to bottom 50 of heat exchanger 12.Once attached, drain pan 76 prevents fluid leakage from bottom 50 ofheat exchanger 12.

Liquid header panel 78 includes top 90, bottom 92, first side 94, secondside 96, inlet opening 98, and outlet opening 100. Liquid header panel78 is substantially rectangular in shape and is configured to coverthird side 56 of heat exchanger 12. Top 90 extends at an approximatelyright angle from an upper end of liquid header panel 78 to attach to3-way mount 58 on top 48 of heat exchanger 12. Bottom 92 of liquidheader panel 78 is open and configured to rest within lip 82 on a firstside of drain pan 76. First side 94 and second side 96 of liquid headerpanel 78 extend at approximately right angles to contain third side 56of heat exchanger 12 from air inlet header 64 to air outlet header 66.Liquid header panel 78 includes inlet opening 98 and outlet opening 100,which are circular and configured to surround liquid inlet 36 and liquidoutlet 38, respectively. Both inlet opening 98 and outlet opening 100include raised lips for cooperating with tubing that conduct liquid toand from heat exchanger 12. Once attached, liquid header panel 78prevents fluid leakage from third side 56 of heat exchanger 12.

Closure bar panel 80 includes top 102, bottom 104, first side 106, andsecond side 108. Closure bar panel 80 is substantially rectangular inshape and is configured to cover and protect fourth side 72 of heatexchanger 12. Fourth side 72 of heat exchanger 12 is considered the“closure bar face” and is used to close off the air and/or liquidcircuit. Top 102 extends at an approximately right angle from an upperend of closure bar panel 80 to attach to 1-way mount 74 on top 48 ofheat exchanger 12. Bottom 104 of closure bar panel 80 is open andconfigured to rest within lip 82 on a second side of drain pan 76. Firstside 106 and second side 108 of closure bar panel 80 extend atapproximately right angles to contain fourth side 72 of heat exchanger12 from air inlet header 64 to air outlet header 66. Once attached,closure bar panel 80 prevents fluid leakage from fourth side 72 of heatexchanger 12.

As shown in FIG. 7, when leakage shield 70 is assembled it surroundsheat exchanger 12. Top 90 of liquid header panel 78 extends outwardlyfrom its attachment to 3-way mount 58 at top 48 of heat exchanger 12.Liquid header panel 78 extends downwardly from top 90 to cover thirdside 56 of heat exchanger such that bottom 92 of liquid header panel 78rests within lip 82 of drain pan 76. Bolts attach bottom 92 of liquidheader panel 78 to the first side drain pan 76. Similarly, top 102 ofclosure bar panel 80 extends outwardly from its attachment to 1-waymount 74 at top 48 of heat exchanger 12. Closure bar panel 80 extendsdownwardly from top 102 to cover fourth side 72 of heat exchanger suchthat bottom 102 of closure bar panel 80 rests within lip 82 of drain pan76. Bolts attach bottom 104 of closure bar panel 80 to the second sideof drain pan 76. Insulation can be provided between heat exchanger 12and leakage shield 70 to prevent air from coming in contact with heatexchanger 12. Leakage shield 70 substantially surrounds, and thereforeprevents any liquid leakage from, heat exchanger 12.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

1. A method of installing a leakage shield on a liquid to air heatexchanger, the method comprising: covering a bottom of the heatexchanger with a drain pan; covering a first side of the heat exchangerwith a liquid header panel; and covering a second side of the heatexchanger with a closure bar panel.
 2. The method of claim 1, furthercomprising: attaching the drain pan to the bottom of the heat exchanger;attaching the liquid header panel to the drain pan and a top of the heatexchanger; attaching the closure bar panel to the drain pan and the topof the heat exchanger.
 3. The method of claim 2, further comprising:welding at least one boss to the bottom of the heat exchanger.
 4. Themethod of claim 3, wherein attaching the drain pan to the bottom of theheat exchanger includes bolting the drain pan to the at least one boss.5. The method of claim 2, wherein attaching the liquid header panel tothe top of the heat exchanger includes bolting the liquid header panelto a mount located on the top of the heat exchanger.
 6. The method ofclaim 2, wherein attaching the closure bar panel to the top of the heatexchanger includes bolting the closure bar panel to a mount located onthe top of the heat exchanger.
 7. The method of claim 1, furthercomprising: surrounding a liquid inlet and a liquid outlet with theliquid header panel.